Identification Symptoms

Die back phase: 

  • The plant begins to die backwards form the top of a branch.
  • Young shoots, leaves and fruits are readily attached, while they are still tender. The greenish colour of the growing tip is changed to dark brown and later to black necrotic areas extending backwards.
  • The fungus develops from the infected twigs and then petiole and young leaves which may drop down or fall leaving the dried twigs without leaves.

Fruit and leaf infection phase: 

  • Fruit and leaf infection is generally seen during rainy season crop. Pin-head spots are first seen on unripe fruits, which gradually enlarge.
  • Spots are dark brown in colour, sunken, circular and have minute black stromata in the center of the lesion, which produce creamy spore masses in moist weather.
  • Several spots coalesce to form bigger lesions .
  • The infected area on unripe fruits become corky and hardy, and often develops cracks in case of severe infection.
  • Unopened buds and flowers are also affected which cause their shedding.
  • On leaves, the fungus causes necrotic lesions usually ashy grey and bear fruiting bodies at the tip or on the margin

Survival and spread:

  • Infection spreads by wind borne spores develop on dead leaves, twigs and mummified fruits in the orchard.
  • Dense canopy is congenial for germination of spores due to high moisture condition.
  • Movement of planting material through infected foliage.
  • Transportation of fruits from high disease prone area.

Favourable conditions:

  • Closer planting without canopy management
  • Dew or rains encourages spore production and its dispersal around canopy.
  • Temperature between 10 to 35  oC with best 24 to 28oC.